The advent of class-based networks has brought new needs for
network traffic control in order to assure a certain QoS level.
Despite the existing proposals, achieving a generic admission
control (AC) strategy for traffic entering these networks is
still an open issue. This paper provides new insights on how
AC shall be accomplished proposing an encompassing AC model
for multi-service class-based networks, which covers both
intra-domain and end-to-end operation, without requiring
changes in the network core and complex AC signaling.

For each service type, AC is distributed and based on both
on-line edge-to-edge monitoring of relevant QoS parameters
and SLSs utilization. Service monitoring, performed at egress
nodes, provides adequate metrics to ingress nodes which take
implicit or explicit AC decisions based on service-dependent
criteria. Although being oriented to flow AC, the model can
easily be applied to SLS AC. SLS auditing and SLS traffic
conditioning are tasks also covered.